Well, of course you can modify the lights in real time (position, intensuty, color) but this ligths are only like a bulb light and doenst really project shadows. ABout the cameras well of course you can have more than one but can render only one ata time! but you can make something to emulate multiple cam render behaviour, for example you can look at model 3D, it was a homework I did using jpct, you can download it from this site. It renders 4 different cameras at a time inside a JFrame.